Railway signaling



E. C. SASNETT RAILWAY SIGNALING Filed Oct. 9, 1925 Nov. 6, 1928.

Patented Nov. 6, 1928.

l narran entras rArENroFFlcE.

. EDWARD C. SASNETT, OF WASHINGTON, DISTRICT 0Fy COLUMBIA. y

RAILWAY SIGNALING.`

Application filed October 9, 1925. Serial No. 61,425.

The present invention relates to railway signaling, and particularly to norinal safety signaling; systems of the direct current type.

The novel features of theinvention will be pointed out in the clail Fig. lshows in a diagrammatic Way one Y andconductors 118 and 119 to the negative system embodying the invention.

Fig. 2 is a detailview illustrating a slowacting relay. y l

Fig. 1 ot the drawingr shows a stretch ot tra-cl; divided into insulated bioclis A, B, C, D, E etc. having a track relay connected. at the entrance end et' each bloei: and a hattery 100 adapted to loe connected to the enit' end. Relays 101 having neutral and polarized contacts are associated Vwith the traclr relays and connected across line Wires 102 and 103 leading to a central station. central station there are two uniformly driven calns 1011 and 105 operating` circuit controllers 106 and 107 ,respectively r1`he raised part c-teach cani extends through an arc oit 120O and are arranged so that when one raised portion passes out of engagement with its circuit controller the other raised aortion siinultaneousl f eneaes its circuitA controller. The circuit controllers when closed connect a battery 108 `across the line Wires 102 and 108. Zhen circuit controiler 100 is closed the positive lpole ot battery 108 is connected to line Wire 103, and `when circuit controiler 10T` is' closed the `positive pole 0'1" the battery is connected to line Wire 10st.. 1t it he assumed that the cams.inake a conipiete revolution every three seconds, 1`cattery 10S will he connected across the line Wires for a period of one second,ysay by switch 106; then connected by switch 107 across the line Wires with reversed polarity for a period cfone second;` and linally dis connected for a period of one second; for each cycle or revolution of the cams.

'With snf'itch 10G closed as shown, the hacl: neutra contacts ot relays 101 yare open and the polarized contacts 0'1"'y these relays are in e their lett hand i'iositions; VUnder theseyconm ditions, current troni the battery `100 associated with the track` relay connected to bloeit E flows in the rails Ao1" block D hy 1Way the toiiowing connections: positive At this ,The connections 'for the station for pole or the'hattery, conductors 109 and 110, polarized contact-s 111 andk 112, conductor 118, front contact 11e of the relay connected tololoc; E, conductor 115, the lower rail ot' hloclr D, the track relay, the upper yrail vot block D, conductor 116, front contact 117,

pole of `battery 100. Current flows in the connections: from the positive noie of the 6U battery 100 associated with the track relay of block D, conductors 120 and 121, contacts 122, 128, conductor 1211, the upper rail of block C., the track relay and the lower rail, conductor 125, contacts 120, 127, and conductors 128, 129 to the negative pole Aof the battery. Current {iov-is in the rails of hlock B by Way` of the following connections: positive pole of the battery 100 associated with the track relay connected 'to block C, conductors 120, 121, contacts 122, 123, conduotors 131, 132, front Contact 117 orx the track relay, conductor "116, the upper rail of block B, the track relay, the lowery rail, conductor 115, `trent Contact 114, conductors 133, 134:, contacts` 120, 127, and conductors 128 and 129 to the negative pole oit the hattery. Current `Hows in the rails of block A by Way of the saine connections as those Y describerd With respect to block D.

It may be here pointed out that the block stations are arranged in groups of `three and that the connections at` stations in the saine `group are different While the connections at corresponding stations oit the several groups are the saine. The stations for blocks B, C and D belong to the saine group While the station -for block E belongs to the next group and is the first station thereof. hlocl; F (not shown) are the saine asthe connections for the stationy for block` C; andthe connections of the station for block Gr (not shown'yare the saine as those for the station o1 loloclrD. A'

7 hen switch 107 rcloses simultaneously with the opening of switch 106 the direction of current in the line Wiresv 102 and 103 `is reversed and the polarized contacts of relays 101 lnoye to their right hand positions While 10o'.

/ the rails of block the back contacts remain open. Current now liows through the rails of block D by way of the connections formerly described, except that the circuit is closed through contacts '111 and 136 instead of through contacts 111 and 112. Current flows through n C by `way of thefollowing connections: positive pole of batteryv100, conductors 120 and V121, contacts 122 and 137, conductor 138, conductor 133, front contact 114, conductor 115, the loweiq rail of block C, the track relay, theupper rail, conductor 116, front contact 117, conductors 132 and 139, contacts 125 and 127, and conduc,A tors 128 and 129 to-the negative pole of the battery.. vCurrentliows vthrough the rails of block B by way ef the following` connections: battery 100,*conductors 120 andl121,

contacts 122 and 137, 'conductor 136, the lower rail of block B, the track relay, the upper rail, conductor 124, contacts 125, 127, and conductors 128 and 129 to the negative pole of the battery. Current iiows in the rails of block A by way of the sameconnections as those described with respect to block D. lhen the switch 107 opens, there is an interval (while the cams are rotating through an angle of120O) when current is cut off from the line wires 102 and 10,3.V

During the interval' in which current is cutoff from line wires 102 and 103, the back neutralcontacts of rrelays 101 are closed, and the polarized contacts 122, 127 and 111 occupy their neutral or middle positions,in

` which they do notengage any of the stationarycontacts. In thisinterval therefore,

current flows through the rails of block D by; way of the following connections: positive pole ofbattery 100, conductors 109, 140,

back Contact 141, conductor 142, the upperl `rail of block D, the track relay, the lower rail, conductor 143, back contact 144 andconductors 145 and 119 to the negative pole of the battery.v Current flows inl the rails of block-C through the` following connections: kpositive pole of battery 100, conductor 120,r back Contact 144, conductors 146` 132,r

front contact 117, conductor 116, the upper rail of block C, the track relay, the lower rail, conductor 115, front contact 114., conductors 133,147, back contact 141. and con#v ductor 129 tothe negativey pole of the battery. Current flows in the rails of block B by way' of connections in all respects simi# lar tofthose described with reference to` f block C, and current flows'in block A. by way the case of block D.

of connections similar to those described inY ltwill be understood from the foregoing that'cu'rrent continuously Hows through the track rails'under normal or safe conditions.-y

However, it is to .be observed that this curi i rent does not flow throughthe rails at all times-iii the sainek direction. Take block D, foi` example; when switch 106 is closed the positive pole of battery 100 is connected 'to the lower rail through contacts 111 and 112 of relay 101 and through the front contact y 114 of the track relay; when switch 107 is closed `the positive pole of the battery isk also connected to the lower rail through contacts 111 and 136 of relay 101` andl front contact 114 of the tra-ck relay. But when current is cut o from the'line wires the positive pole of the battery is connected to the upper rail of block D through back ceny tact 141 of relay 101. Thus with the assumption that the cams make a complete revolution every three seconds, current will flow in the rails of block D in one direction se f for a period'xof two seconds through the polarized contacts of relay 101 and for a period of one second through the back neu- Atralcontacts of this relay. Again, take the is connected to the lowerrail through polai'ized contacts 122 and 137'and front contact .114 of the track relay connected to block D; and when currentis cut off from theline wires, the positive pole ofthe battery `is connected `to the upper rail ofblock yC through back contact 144 and front contact 117. Thus also in the case of blo'ckC, there will be a flow of currentthrough the rails in one direction for a -period of two seconds and a flow inthe opposite direction fora period of one second.. Finally, take thegcase of block B l/Jhen switch 106 is closed, the positive pole of the battery isconnected `tothe upper rail of block B through the contacts 122 and 123 of relay -101and the front contact 117 of the track relay. Then switch 107 is closed the positivev pole of the battery rail through conr is connected tothe lower tacts 122 and 137V of relay 101. VWhen current is cut olf from the line wires, the positive pole of the batteryk is connected to the upper rail of block B through back contact 144 'of relay 101 and front'c'ontact 117 of the trackrelay. Here again, there will bc a flow *ofcu'rrent' hrough the rails in one di- 'rection'for a'k period rof two seconds and a a period How in lthe opposite direction forv u of onesecond.. It will be cleartherefore through the rails of the blocks iirstfor two .seconds in yone direction and then for one` vwhen a trackrelay is deenergized.v Assume the track .relay connected to block E to be deenergized.

block D, for the reason that the trackcire Htly 'that undergnorinal conditions currentflows A During the two second period l. when switches 106 and 107 are clos-ed, there will be no flow `of current. in the rails of.

use'

ltrack relay..

cuitconnections through contacts 111, 112 and 136 are open at the front contact 114. During the one second period when cur rent is cut oit ironi` the line wires, however, there will be a ilow ofeurrent in the rails of block D through the back contacts 144 and 141, the positive pole of the batterybeing connected to the upper rail of block D. During this one secondV interval therefore current will also llow through the rails of block C through the back contacts 144 and 141 of relay 101 and the iront contacts 114 and 117l of the track relay, the aositive pole of the battery being, connected to the upper rail. 'During this one second period when current is cut off from the line wires, current will flow through the rails of block B by way of the back contacts of vrelay. 101 and the 'front contacts of the track relay`the positive pole ot the battery being connected to the upper rail; Cnrrentwillalso llow in the rails ot' block A by connections `siniilar in all respects to those for block D. At the end of the one second period in which current is cut olf 'from the line wires, switch 106 closes and the polarized contacts oitv relays 101 niove to their left hand position. Therefore duringl the one second interval in which switch 106 is closed no current flows in the rails of block D. Current flows through the rails of block C `'through the contacts 122, 123 and 127, 126 of relay 101,

the lpositive pole of the battery being con-V nected to the upper rail. `Current flows through the rails of block B through the contacts 122, 123 and 126, 127 oi relay 101 and through the front contacts 114 and 117 of the track relay. y through the rails of block A by 4way ot' contacts 111 and 112 and the rontrcontacts of At the endoil thek one` the track relayY second period inwhich current isy connected to the line wires through switch 106, switch 10i closes and the polarized contacts of re` lays 101 move to their right hand positions,

During' this period, no current'will dow" through the rails of block D since the con ection through the polarized contacts of relay 101 is open at front contactv 114 oi the current will flow through the rails C, as 'the connections through contacts 125y f and 137 are open atk thefront contacts-1141 and 117 of the vtrack relay. During this interval current will tlow through theV rails of block B by way of' the contacts 125 and 137. f i

Fig. 2 shows" a-typeofslow acting relay which may be employed in the system. y As shown, this relay comprises .a solenoidhav ing piston operating in va dash pot and con nec-ted at its other end toa bridgeuipiece which when the solenoid is energized bridges the iront contacts 160 and when the sole- Curient flows lAlso during this interval nol ofl block a plunger connected at .oneendto a` y relay will drop.

noid isr deenergized bridges `the back kcontacts 163. As long as the `solenoid is enn ergized periodically for a period of two seconds and deenergized for a period of one second', contacts 160 will be bridged, but when the solenoid is periodically energized for aperiod of, only one secondand doenergized for a period of two seconds the bridge member will maintain an engagement with back contacts 163.

From the above it will bel understood,

`that when a track relay is deenergized, current will tion* through the rails of the block immediately in rear for a period of one second every three seconds of, say, positive polarity; in the second block in rear current Vof the saine polarity will flow for a period of two seconds every three seconds; andin the third block in rear current will flow of the saine polarity for a period of two seconds `and current of negative polarity will,V

flow for a period of onesecond. That is, in

larized relay 150 connected by a lori7 resist-` ance circuit to contacts engaging the rails. Under norma-lor safe conditions-the polarized armature 151 of this relay vibrates kin unison with the reversals of current inthe rails, alternately engaging stationary conv tacts 152 and 153 andthereby alternately closing the circuits of relays 154 and 155 which control the circuitsy of` clear, caution and` danger lamps 156,157 and 158, respectively; he relays 154 and lrare slow acting relays vand accordingly hold up their ar-- matures so long as the interval between successive energizations `thereof doesy not siub-l stantially exceed two seconds. Therefore under clear conditions the circuitof` clear lamp `15G will be completed through the irontfcontacts 159 and 160. Under caution conditions, armature contact `151 moves from a `central neutral position into engagement with stationary contact 152 and maintains I such engagement for a `period ,of two sec- "onds, thenniovesback to its cent-ral position .whereinit remains tor a period ofone sec'- ond and` then again ymoves into engagement 'with contact 152, Hencethe circuit of re-` lai 155 will be intermittently closed so as to hold this relay up. butthe circuit of relay 154 Lwillnotfbeclosedfand hence this therefore the 'cireuit'of clear lamp 156 will be interrupted ,at `front contact 159 and the "U nder caution conditions at back contact 161 andcfront contact 160;

- Under danger conditions, the polarized con- Aio - with contactf152 for fby said relay.

not open its back contact when energizedfor a period of only onev second. Hence this relay rwill drop and remain dropped when intermittently energized for onlyone second during three second periods. Any s uitable knownr device, such as dash potvinay be' provided to effect this result. Hence un-r der danger conditions the circuitot caution llamp is open at frontcontact 162, and they circuit of danger lamp .158 is closedv at back contacts 161 and 163.. f

I claim:

y1. A railway signalingsystem comprising a track divided into insulated blocks, track relays connected across therails at the en-` ftrance ends 'of the blocks, local sources-of direct current adapted to be connected across the rails at the Aexit ends. of the blocks through connections controlled by said tracky relays, selective meansoperated from a cenl'trai station controlling said connections :tor

periodically-.r versing said connections, a

l vehicle traveling-on the track having` a polarizedV relay connected across the track-rails.

and train governing mechanism controlled f 2. A railway signaling system comprising a track ldividedinto blocks, `a track relay connected acrossthe rails `at the entrance end of each block, constantly operating synchrolnizeddevices associated with the'- track relays and operating jointly therewith to connect local sources. of direct 'current across the rails at "the exit. ends of' the yblocks and to reverse .periodically 4the connections of said sources'to the rails and train control devices responsive :tothe currents. flowing through the rails. f f f ,y

3.' A railway signaling system'comprising a trackdivided into blocks, a trackielay connected across the rails at the entrance end of f each block, synchronized devices f associ-y ated withq the track relays andcpe'rating jointlytlierewith to connect local sources 'ot direct current across the rails at the exit ends ot', the blocks and to reverse periodical-r ly vthe connections of said sources tothe rails, a vehicletraveling on the track havy ing a polarized relay connected across the track'rails and train control devicesv gov-` erned by said polarizedy relay. f 'r '4. A railway signaling system 'comprisingV a track divided into"blocks, a, track relay', connected across the rails atthe entrance end.

successively and periodically applying elecof each block, continuously operatingy synl chronized devices,` associated with the. track Relay 155 is construct-` relays and operating jointlyftherewith to ,connect` electricalenergy acrossV the rails at the exitends of theblocks and to periodically vary the characteristicsk ot said energy c andtrain control mechanism selectively responsive to the character of energy flowing throughthe track rails. Y Y

6. A railway traffic controlling system comprising in combination, a track divided into insulated blocks, a normally-energized track relay connected acrossy the rails of each block, means operating when a track relay ,isfdeenergized to kapply currents of different characteristics'respectively to the two blocks immediately in rear of said deenergized relayand to apply currentoitsaid two characteristics alternately-and periodie w cally to the third block in rear, and signals for the blocks selectively controlled by said currents.

7. A railway traine controllingy system comprising in combination, timingmeans'tor alternately applying'to; the rails of each block currents of different characteristics, a track 'relay for each block continuously en-. ergized byy said currents, said timing means operating Vwhen a track .relay isA deenergized f to apply current ot' Vone characteristic to.; the block immediately in ,rear ofthe de-4 energized relay and'current having another characteristic'r to the second block 1in' ',rear, and signalsftor the blocks selectively controlled said currents.

comprising. in combination, a trackjdivided into insulated blocks, a track relay connected across the rails of each block, timing means controlledk by: the track re'lays for continuously applying current to the rails-ofthe blocks underfnormal conditions, said means operating `when a ,relay is `deenergized tol 'apply current inteimittentlyto the rails ofk va blockfin the rear,` clear signals for-the 811A railwayk traffic controlling. system l i blocks displayed only while current is continuously applied tothe rails,and caution signals-"displayed while current is intermittently-applied. f f c `9. yA railway ytrattic controlling vsystem comprising in combinatiom, af conductor y,

divided into Vinsulated sections,i"means for the sections of said condnctoinnder clear trafnais actuated by said translating device ,iic conditions, ineans for intermittently apselectively accordingto the character of curplyng current to said sections of one of said rent received. 10 characters under caution conditions and of In testimony whereof I hereunto affix my 5 the other character under danger conditions, signature.

a vehicle having a translating device electrically connected to said conductor, and sign EDWARD C. SASNETT. 

